#include <cstdio>
#include <iostream>
#include <cstdlib>
#include <string>
#include <unistd.h>
#include <pthread.h>
#include <mutex>

//pthread_mutex_t glock=PTHREAD_MUTEX_INITIALIZER;
int ticket = 1000;

struct ThreadData
{
    std::string name;
    pthread_mutex_t *lockp;

    ThreadData(std::string name, pthread_mutex_t &lock) : name(name), lockp(&lock)
    {
    }

    ~ThreadData()
    {
    }
};

// 加锁的粒度尽量要细一些，尽可能不要包含太多的非临界区代码
void *route(void *arg)
{
    ThreadData* td=static_cast<ThreadData*>(arg);
    while (1)
    {
        pthread_mutex_lock(td->lockp);
        if (ticket > 0)
        {
            usleep(1000);
            printf("%s sells ticket:%d\n", td->name.c_str(), ticket);
            ticket--;
            pthread_mutex_unlock(td->lockp);
        }
        else
        {
            pthread_mutex_unlock(td->lockp);
            break;
        }
        usleep(321);
    }

    return nullptr;
}

int main(void)
{

    //std::mutex mtx;
    pthread_mutex_t lock;
    pthread_mutex_init(&lock,NULL);
    pthread_t t1, t2, t3, t4;
    ThreadData *td1 = new ThreadData("thread 1", lock);
    pthread_create(&t1, NULL, route, td1);

    ThreadData *td2 = new ThreadData("thread 2", lock);
    pthread_create(&t2, NULL, route, td2);

    ThreadData *td3 = new ThreadData("thread 3", lock);
    pthread_create(&t3, NULL, route, td3);

    ThreadData *td4 = new ThreadData("thread 4", lock);
    pthread_create(&t4, NULL, route, td4);

    pthread_join(t1, NULL);
    pthread_join(t2, NULL);
    pthread_join(t3, NULL);
    pthread_join(t4, NULL);

    pthread_mutex_destroy(&lock);

    return 0;
}